Astronomy: Study Uncovers 12 Nearby Stars
- By Robert Roy Britt Senior
Science Writer 01/01/2002
WASHINGTON D.C. - With astronomers finding galaxies
that are billions of light-years away and spotting
stars thousands of light-years distant in our
own galaxy, you'd think they'd know about all
the stars in our backyard.
Not so. Today, researchers announced a dozen newly
found stars all within 33 light-years of Earth
-- next-door neighbors by cosmic measures. All
the stars were found in the southern sky, where
surveys are less comprehensive than from the Northern
discoveries were made by a team of researchers
led by Todd Henry of Georgia State University.
Henry and his colleagues are working to build
a 3-D map of the local sky.
nearest known star is Proxima Centauri, which
is 4.2 light-years away. The nearest of the newly
discovered objects is 20 light-years away, putting
it at 55th on the list of closest stars.
stars come in three configurations: Seven are
alone in space; two orbit each other in what's
called a binary star system; and the remaining
three are in a rarer three-star system, all orbiting
had gone unseen because they are thousands of
times fainter than stars that can be seen with
the naked eye. The nearest one is only about a
third of the size of the Sun and emits less than
1 percent as much light.
of the stars is a white dwarf. The others are
dwarfs are sometimes counted as part of "dark
matter," somewhat mysterious material that
can't be seen but that researchers know must exist
based on the amount of gravity at work in galaxies.
dwarf stars are typically about the size of Earth,
but they can be as massive as the Sun. That makes
them dense. A teaspoonful of a white dwarf weighs
as much as an elephant. White dwarf stars are
the end of the evolutionary road for smallish
stars, ones that could not generate the spectacular
explosions that mark the death of larger stars.
of their proximity, the newly identified stars
could prove useful as targets for planet hunters.
of the new stars provides a fresh target where
we can look for planets, and ultimately, for life
on those planets," Henry said here at a meeting
of the American Astronomical Society.
stars were studied with two telescopes at the
Cerro Tololo Interamerican Observatory in Chile.
The research team included Georgia State's Wei-Chun
Jao and John Subasavage; Phil Ianna of the University
of Virginia; Rene Mendes of the European Southern
Observatory; and Edgardo Costa of the Universidad
Coverage of the 2002 AAS Meeting